1. Field of the Invention
The present invention relates to an enclosure for receiving and storing digitally coded disks and, more particularly, to an enclosure which is configured to facilitate insertion and removal and to provide secure storage of a disk in a manner which safeguards the disk's information bearing surface against blemishes and scratches which may pierce its protective layer.
2. Description of the Prior Art
In recent years disk-form recording and storage media for audio, video and digital signals have become increasingly available. Particularly popular are compact disks known as CDs, in which audio or video information is digitally recorded by use of a laser beam and then read optically by a laser beam. Typically, information is placed on only one surface of the disk in digital form as a track of microscopic pits in a thin, reflective metallic layer. Similar disks, known as CD-ROMs, are employed to store digital information for use as read only and other memories in computer and other applications.
Typically, compact optical disks comprise one or more coating layers deposited upon an aluminum platter. Optical recording techniques deposit digital information on the disk and within the coatings in any one of a number of well known ways. A protective plastic coating on the surface of a CD or CD-ROM protects the information on the disk from environmental damage, such as from dust, debris, heat, fingerprints, and the like. Only significant scratches and blemishes which pierce the protective layer can interfere with the laser light beam which "reads" the information on the disk. One common cause of such damaging scratches and blemishes is the molded plastic storage enclosures or boxes of the types presently used to store such disks. These boxes contain many sharp plastic edges, particularly at the access opening to the box cavity where the arcuate, finger-grip cut-out portions formed in the box side walls can ride across and scratch or gouge the protective layer on the disk during disk insertion or removal and, thereby, damage the information-bearing surface of the disk. Another common cause of disk surface damage are the gripping tabs present within the cavities of some boxes and which are intended to grip the upper and lower surfaces of the disk near its peripheral edge to securely retain the disk within the cavities. The constant insertion of the disk into and removal of the disk from the gripping tabs abrades the protective layer and damages the information bearing surface of the disk. This is particularly troublesome when it is appreciated that compact disks are not made to particularly close tolerances and that there is significant disk thickness variation from the nominal 1.2 mm thickness of such disks. Disks which are thicker than nominal take a particularly severe beating upon insertion into and removal from such gripping tabs.
Probably the most widely used packaging and storage enclosure for compact disks comprises a three piece assembly consisting of a base, an insert or tray on which the disk is supported, e.g., by a center projection which engages the periphery of the aperture in the center of the disk, and which is positioned within the enclosure base, and a cover which may be hinged to the base and serves to enclose the disk-bearing tray within the cavity defined between the base and the cover. Enclosures of this type, although the current standard in the industry, are relatively expensive to manufacture, bulky and inconvenient to use.
Other types of enclosures for optical disks are also well known. For example, the enclosure disclosed in U.S. Pat. No. 4,905,217-King et al. comprises a one-piece structure providing a box-like enclosure open at one end wall for insertion and removal of a disk therethrough into the box cavity and includes a pair of gripping tabs at the opposite end wall within the cavity. The enclosure disclosed in U.S. Pat. No. 4,627,531-Clemens comprises generally rectangular top and bottom portions interconnected about their periphery by side portions for forming a box-like enclosure defining a cavity for receiving a disk therein and which is open at one end, the open end being covered by a closure strip which is movable along a guide path between enclosure open and closed positions. Still another disk enclosure, shown in U.S. Pat. No. 4,687,101-Barker et al., comprises a housing having spaced top and bottom wall surfaces, opposed side walls and an end wall forming a three-sided enclosure open at the opposite end for inserting and removing a disk therethrough into and from the enclosure, the end wall being formed with a V-shaped notch which opens into the housing for securely retaining the disk within the housing during transportation or handling.
Each of these enclosures suffers from one or more shortcomings which make it either unsatisfactory or not particularly desirable for use as an optical disk enclosure. Either the enclosure is undesirable because it is bulky, expensive to manufacture and inconvenient to use or it is unsatisfactory because it is not particularly safe for insertion, removal and storage of an optical disk therewithin without substantial risk of damaging the information bearing surface of the disk. Accordingly, there remains a need for a simple, inexpensive and easy to use optical disk enclosure which is configured to facilitate safe insertion and removal of the disk therein and therefrom, which securely and safely stores the disk therewithin and which safeguards the disk's information bearing surface against blemishes and scratches which may pierce its protective layer.